The overall goal of DECIPHER is to investigate whether racial/ethnic differences exist in the underlying risk factors for chronic cerebral microbleeds in patients with primary ICH and to determine the prognostic impact of microbleeds in a predominantly underserved ICH population. Intracerebral hemorrhage (ICH) is a devastating and disabling disease with 30 day mortality rates estimated at 35-52%. Primary ICH is 2-3 times more common in many underserved populations, including blacks. Hypertension and cerebral amyloid angiopathy have been identified as common risk factors for primary ICH in the general population. Microbleeds, clinically silent small, chronic hemorrhages identified on gradient echo (GRE) MRI, are present in approximately 70% of patients with primary ICH and are hypothesized to be a marker of a hemorrhageprone vasculopathy. In patients with cerebral amyloid angiopathy, the number of microbleeds has significant prognostic value, predicting future risk of ICH, poor long-term neurologic outcome, and cognitive decline. Our recent pilot data suggest that black patients presenting with ICH have a significantly greater number of chronic microbleeds compared to whites. However, the underlying etiology and significance of this finding are unknown. The 4 specific aims of this longitudinal, MR imaging cohort study are: 1) To quantify by race/ethnicity the prevalence, lesion burden and risk factors of chronic cerebral microbleeds in patients with primary ICH; 2) To quantify the prognostic impact of initial microbleed burden by race/ethnicity; 3) To quantify the long-term rate of development of new microbleeds by race/ethnicity and to correlate this rate with neurologic and functional outcome; and 4) To perform a genetic substudy to explore genetic risk factors for ICH and microbleeds in this underserved population. A total of 189 patients with primary ICH will be enrolled and followed for up to 4 years. Repeat MRIs including GRE sequences will be performed at years 1 and 3 and evaluated for progression of disease (new microbleeds, recurrent ICH, ischemic stroke, and leukoaraiosis). Additional measures to be evaluated will include demographic information, presence and control of vascular risk factors including hypertension, apolipoprotein E status, and functional outcome. This project will not only provide insight into the significance of microbleeds in underserved ICH populations, but will also provide pilot data for design of future intervention trials of secondary prevention measures.